Sebastian was encountered only in the Fourth timeline that gave rise to the events of Legacy of Kain: Blood Omen 2.[1] As such, he was either sired by Vorador or one of his descendants sometime between the Collapse of the Pillars and the Rise of Kain's vampire army.[2] When the army rose to power and began to conquer Nosgoth, Sebastian served as one of its leaders, but for uncertain reasons - whether because of jealousy, the promise of power or a perceived lack of "value" from Kain[3] - Sebastian betrayed Kain, selling himself to the Sarafan Lord and arranging an ambush that would cost his former leader the war.[4]

When the battle commenced, the ambush was successful, and Sebastian's absence alerted Kain to his betrayal. The Vampires were defeated, and Kain was left for dead by the Sarafan Lord. In the centuries that followed, Sebastian became a major player in the new Sarafan-dominated Nosgoth - he was the highest-ranked Traitor vampire seen in Legacy of Kain: Blood Omen 2. His prestige was such that he ranked among the only non-Hylden Sarafan aware of the existence of the Device.[5]

Two centuries after the Battle of Meridian, after his awakening, Kain sought out the Cabal - the Vampire resistance movement - and made his way through the Lower City. While searching for Sanctuary, he came across a small courtyard, next to the City Reformatory, which was covered in dismembered Human corpses, Blood and gore - the result of "sloppy" feeding.[6]

Though Kain did not yet recognize his former compatriot, he had interrupted Sebastian, who was responsible for the massacre. Sebastian acknowledged Kain as "a voice from the past" before retreating across the city's rooftops, claiming that he was required elsewhere.[7] Kain attempted to follow, and was able to establish that the Vampire disliked him and probably served the Sarafan Order. Sebastian fled into the night, jumping beyond Kain's reach.[8]

Shortly after Kain rescued Umah from the Sarafan Keep, he and Vorador learned that the Sarafan Lord was using the powers of the Nexus Stone in the Main Factory of the Industrial Quarter.[9][10] Realizing he could use the Stone to counter the threat of the Soul Reaver, Kain traveled to the Quarter, attempting to steal it. Sebastian, however, sensed that Kain was approaching, and instructed his Glyph guards to prevent his enemy from reaching the chamber at all costs.[11]

As Kain navigated the complex, Sebastian was forced to confront him in the Power Chamber. In the light, Kain finally recognized him, and the two fought for control of the Stone.[BO2][12] After winning the battle, Kain interrogated the charred, dying Vampire. Sebastian informed Kain that the stone's portal led to the Device - a machine which he knew would spell Kain's destruction - but he did not know the specifics of its operation.[13] As Sebastian perished, Kain - scorning his foolhardy ambitions - absorbed the Dark Gift Berserk from his veins and claimed the Nexus Stone, destroying the Main Factory in the process.[14]

"And now, your time is up. Your death will only make me stronger. I hope that knowledge comforts you, in your grave."

Sebastian was aware of Kain's revival even before their first meeting; in In Darkness We Gather, he speaks of "rumors" of Kain's return,[7] a phrase that would also be used later in A Question of Faith (chapter) by Marcus.[15]Faustus had already had an encounter with Kain (at the Grand Hotel at the end of Welcome to Meridian), an opportunity for him to report the information to the Sarafan. Also in their initial meeting, Kain chased Sebastian across some rooftops, with Sebastian demonstrating further similar traits in common with Marcus, such as an extended range/height Jump and a chase that results only in the antagonist retreating to the next obstacle[BO2].

Sebastian's ranking in both the Vampire Army and the Sarafan Order is unclear; his close relationship to Kain (and his damaging betrayal) would suggest Sebastian was very close to Kain and likely one of the army's commanders. Likewise, he may have been the highest-ranked non-Hylden member of the Sarafan Order seen, and his dialogue suggests another close (and supposedly "more equal") relationship with the Sarafan Lord.[3] However, though clearly associated with the Sarafan Order, Sebastian initially denies working for them, perhaps indicating he considers the human members of the order beneath him.[8] Only later did he admit to working for the Sarafan Lord, considering the regnant Hylden his "master".[3][16]

The usage of Sebastian's Dark Gift, Berserk, is inconsistent in the manner in which Sebastian uses it - Sebastian only uses a regular combo and regular power moves, none of which resemble the Berserk combo)[BO2]. This is because the Berserk gift itself underwent changes during development, originally being called Speed and allowing Kain a time manipulation effect - similar to Slow Time from Blood Omen and the Time Reaver's spell from Legacy of Kain: Defiance. Sebastian uses a prominent Speed-like effect in his boss battle.[17] and his character is referred to as "spd" in debug messages[BO2].

Sebastian is notably committed to his cause in the boss battle, knowingly attempting to destroy the Nexus Stone, an act which would have killed himself and Kain in the process.[18][BO2]

As Sebastian dies, Kain offers to spare Sebastian's life; an offer which they both acknowledge is a poor lie.[19] Throughout the entirety of the series, Kain has rarely, if ever, told direct lies to any character.[20]

Sebastian's character model is used to represent generic minor members of Kain's Vampire Army in the Blood Omen 2 opening video - a dreamed recollection of the Battle of Meridian.[BO2]

In the original game scripts, Sebastian is not encountered (or does not speak and is not commented upon by Kain) until the boss battle at the Nexus Stone. His appearance is accompanied by a flashback which depicts his betrayal during the Battle of Meridian, with Sebastian shown beside Kain giving a signal for the Sarafan to ambush them. In this version Sebastian is described in stage directions as "young, handsome and arrogant. Think Feyd from Dune". The removed final line from game files is also present.[BO2-Cut]

↑Kain:"They thought once before they had destroyed us. Yet you proved them wrong. You created a new race, something I could never do, and from that race, I had my army." Crystal Dynamics. Legacy of Kain: Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.

↑ 3.03.13.2Sebastian:"Did you think I would serve, while you ruled Nosgoth? You, and not I? The Sarafan Lord knows how to value me. I am to rule by his side, and achieve what you never could." Crystal Dynamics. Legacy of Kain: Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.

↑Kain:"Your master knows his days are numbered. I might have spared your life by asking that you join me, but I learned that lesson two hundred years ago. You arranged the ambush that destroyed my army. You sold yourself to our enemy." // Sebastian:"I dealt the blow that cost you the war. Glorious, was it not? So many killed, so quickly. And all my doing." Crystal Dynamics. Legacy of Kain: Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.

↑Umah:"I was in the heart of the main factory in the Industrial Quarter. Before the guards discovered me, I had found a huge central chamber that housed some kind of magic portal. This portal looked into a…place, the likes of which I had never seen before. And this portal was held open by a single source of magic, a stone set on a pedestal. Vorador, I believe it was the Nexus Stone." Crystal Dynamics. Legacy of Kain: Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.

↑Glyph Guard:"Sire, a body! We found a body, sire!" // Sebastian:"It won’t be the last. He’s here. I sense the taint of his overblown arrogance. Tell the guards in the power chamber. He must not be allowed to approach the Nexus Stone." // Glyph Guard:"Who is it, sire?" // Sebastian:"An old friend, who will learn his place in the world at last. If you see or hear anything out of the ordinary, report to me at once." Crystal Dynamics. Legacy of Kain: Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.

↑Kain VO:"The fiend that dogged my shadow showed himself at last, and in the light, I knew him. Another visage from my past..." // Kain:"Sebastian! It is you who have been following me." Crystal Dynamics. Legacy of Kain: Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.

↑Kain:"What is the purpose of this device? How will it serve the Sarafan Lord?" // Sebastian:"Alas, he has not entrusted me with that knowledge. But soon, everyone will know it. His plans are even now coming into fruition." Crystal Dynamics. Legacy of Kain: Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.

↑Sebastian:"It lies beneath Meridian. Seek for it, if you will. I die happy in the knowledge that all your efforts will be wasted." // Kain:"Oh Sebastian… Our destiny could have been glorious. The land was ours for the taking. History would have been rewritten in our image. But not everyone shared my vision. And now, your time is up. Your death will only make me stronger. I hope that knowledge comforts you, in your grave." Crystal Dynamics. Legacy of Kain: Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.

↑Kain:"Tell me of the Nexus Stone, and this portal. What is its purpose here? Speak, and I will spare your life."// Sebastian: (Laughs and coughs)"Come, Kain. You lie in your throat and we both know it. You are going to kill me."//Kain:"Indulge me then, before you die." Crystal Dynamics. Legacy of Kain: Blood Omen 2. (Eidos Interactive). PlayStation 2. (March 19, 2002) Transcript.